By Thu Thu Aung YANGON (Reuters) - Rohingya Muslim insurgents said on Saturday that 10 Rohingya found in a mass grave in Myanmar's troubled Rakhine state last month were "innocent civilians", and not members of their group. Myanmar's military said earlier this week its soldiers had killed 10 captured Muslim "terrorists" during insurgent attacks at the beginning of September, after Buddhist villagers had forced the captured men into a grave the villagers had dug.